1,436 research outputs found

    Correlation of Number of Vascular Bundles and Cross-Sectional Area of Corn Stem

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    The investigations show the largest number of vascular bundles in the first and second internodes above the root system. In general the number of vascular bundles varies with cross-sectional area of internodes. In small stalks the number of bundles per unit area is slightly greater than in large stalks, and in internode above the ear slightly greater than in internodes below the ear

    FORESTRY FOR WILDLIFE HABITAT IMPROVEMENT. Nebraska Cooperative Extension Service EC 81-1747, EC 80-1747

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    Wildlife cannot exist without food and protective cover. Natural and planted woodlands contribute significantly to these essentials. This circular describes habitat needs of wildlife, recommends forestry practices for habitat improvement, and gives examples of practices to improve habitat for pheasant, quail, and deer. Variety, rather than uniformity of vegetation, benefits most wildlife species. Management which results in a diverse plant community with many stages of growth can increase the numbers and species of wildlife. Techniques which create improved conditions for woodland wildlife are fundamentally the same as those designed to grow good timber

    Development of the Vascular System of Corn

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    The body of a plant is a cooperative system of cells, tissues, and organs. Yield is a function of the cooperation of these structures. Viewing the plant from this angle a knowledge of the kinds, relationships and time of formation of tissues of Zea mays is essential for an understanding of the factors which influence yield

    Perceptions of Retirement Savings Relative to Peers

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    Do individuals’ perceptions of how much others save for retirement influence their own long-range financial saving decisions? In this study, social comparison theory was used as a theoretical touchstone for understanding the impact of interpersonal perceptions on saving behavior. Respondents (N = 224) reported not only the amount they had saved for retirement during the previous year, but they also reported perceptions of the magnitude of their savings relative to peers and completed 6 psychological scales related to retirement planning. A 2-stage ordinary least squares (OLS) regression approach was used to examine: (a) the extent to which nine demographic indicators were predictive of individuals’ retirement savings practices, and (b) whether unexplained savings from the initial regression model could be hierarchically predicted using the 6 psychological scales and perceptions of one’s savings relative to peers. The findings suggest that social comparisons do account for savings practices over and above demographic and psychological indicators. Results are discussed in terms of how individuals’ implicit social comparisons might shape not only their perceptions, but also their saving behavior

    Study of the Weeds of Alfalfa Fields of Iowa

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    During the past few years a study has been made of the weeds occurring in the alfalfa fields of Iowa, and of their effect upon crop production. The work reported here was clone in the summers of 1928 and 1929

    Long‐Term Responses Of The Kuparuk River Ecosystem To Phosphorus Fertilization

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    Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/117218/1/ecy2004854939.pd

    Associations between socioeconomic status, obesity, cognition, and white matter microstructure in children

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    IMPORTANCE: Lower neighborhood and household socioeconomic status (SES) are associated with negative health outcomes and altered brain structure in children. It is unclear whether such findings extend to white matter and via what mechanisms. OBJECTIVE: To assess whether and how neighborhood and household SES are independently associated with children\u27s white matter microstructure and examine whether obesity and cognitive performance (reflecting environmental cognitive and sensory stimulation) are plausible mediators. DESIGN, SETTING, AND PARTICIPANTS: This cross-sectional study used baseline data from participants in the Adolescent Brain Cognitive Development (ABCD) study. Data were collected at 21 US sites, and school-based recruitment was used to represent the US population. Children aged 9 to 11 years and their parents or caregivers completed assessments between October 1, 2016, and October 31, 2018. After exclusions, 8842 of 11 875 children in the ABCD study were included in the analyses. Data analysis was conducted from July 11 to December 19, 2022. EXPOSURES: Neighborhood disadvantage was derived from area deprivation indices at participants\u27 primary residence. Household SES factors were total income and highest parental educational attainment. MAIN OUTCOMES AND MEASURES: A restriction spectrum imaging (RSI) model was used to quantify restricted normalized directional (RND; reflecting oriented myelin organization) and restricted normalized isotropic (RNI; reflecting glial and neuronal cell bodies) diffusion in 31 major white matter tracts. The RSI measurements were scanner harmonized. Obesity was assessed through body mass index (BMI; calculated as weight in kilograms divided by height in meters squared), age- and sex-adjusted BMI z scores, and waist circumference, and cognition was assessed through the National Institutes of Health Toolbox Cognition Battery. Analyses were adjusted for age, sex, pubertal development stage, intracranial volume, mean head motion, and twin or siblingship. RESULTS: Among 8842 children, 4543 (51.4%) were boys, and the mean (SD) age was 9.9 (0.7) years. Linear mixed-effects models revealed that greater neighborhood disadvantage was associated with lower RSI-RND in the left superior longitudinal fasciculus (β = -0.055; 95% CI, -0.081 to -0.028) and forceps major (β = -0.040; 95% CI, -0.067 to -0.013). Lower parental educational attainment was associated with lower RSI-RND in the bilateral superior longitudinal fasciculus (eg, right hemisphere: β = 0.053; 95% CI, 0.025-0.080) and bilateral corticospinal or pyramidal tract (eg, right hemisphere: β = 0.042; 95% CI, 0.015-0.069). Structural equation models revealed that lower cognitive performance (eg, lower total cognition score and higher neighborhood disadvantage: β = -0.012; 95% CI, -0.016 to -0.009) and greater obesity (eg, higher BMI and higher neighborhood disadvantage: β = -0.004; 95% CI, -0.006 to -0.001) partially accounted for the associations between SES and RSI-RND. Lower household income was associated with higher RSI-RNI in most tracts (eg, right inferior longitudinal fasciculus: β = -0.042 [95% CI, -0.073 to -0.012]; right anterior thalamic radiations: β = -0.045 [95% CI, -0.075 to -0.014]), and greater neighborhood disadvantage had similar associations in primarily frontolimbic tracts (eg, right fornix: β = 0.046 [95% CI, 0.019-0.074]; right anterior thalamic radiations: β = 0.045 [95% CI, 0.018-0.072]). Lower parental educational attainment was associated with higher RSI-RNI in the forceps major (β = -0.048; 95% CI, -0.077 to -0.020). Greater obesity partially accounted for these SES associations with RSI-RNI (eg, higher BMI and higher neighborhood disadvantage: β = 0.015; 95% CI, 0.011-0.020). Findings were robust in sensitivity analyses and were corroborated using diffusion tensor imaging. CONCLUSIONS AND RELEVANCE: In this cross-sectional study, both neighborhood and household contexts were associated with white matter development in children, and findings suggested that obesity and cognitive performance were possible mediators in these associations. Future research on children\u27s brain health may benefit from considering these factors from multiple socioeconomic perspectives

    Favorable outcome of early treatment of new onset child and adolescent migraine-implications for disease modification.

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    There is evidence that the prevalence of migraine in children and adolescents may be increasing. Current theories of migraine pathophysiology in adults suggest activation of central cortical and brainstem pathways in conjunction with the peripheral trigeminovascular system, which ultimately results in release of neuropeptides, facilitation of central pain pathways, neurogenic inflammation surrounding peripheral vessels, and vasodilatation. Although several risk factors for frequent episodic, chronic, and refractory migraine have been identified, the causes of migraine progression are not known. Migraine pathophysiology has not been fully evaluated in children. In this review, we will first discuss the evidence that early therapeutic interventions in the child or adolescent new onset migraineur, may halt or limit progression and disability. We will then review the evidence suggesting that many adults with chronic or refractory migraine developed their migraine as children or adolescents and may not have been treated adequately with migraine-specific therapy. Finally, we will show that early, appropriate and optimal treatment of migraine during childhood and adolescence may result in disease modification and prevent progression of this disease
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